While I'm a big fan of noise especially from drone synthesizers, I don't enjoy listening to feedback from a particular frequency.
To me the tone controls on the guitar have a sweet spot and I just leave it there. The same goes for analog synthesizer settings only since you're looking modulation one dial setting affects another so you're always finding that sweet spot.
guitars have a lot of modulation control over the oscillating strings (oscillators) using fingers, palms, body for vibrato, bending, muting etc.